The invention relates to a tunable laser source, and the reduction in the loss and the size can both be achieved in a tunable laser source having a power monitor and a wavelength locker function. A tunable laser is formed of a semiconductor optical amplifier and a resonator, and one of the two output light beams split from part of the light within the tunable laser by a 2×2 type optical splitter is incident into a light intensity monitor, and the other is incident into a wavelength locker.

A semiconductor laser module that includes a package accommodating therein a plurality of optical components, includes: a semiconductor laser device that emits laser light toward one end side in the package; an optical fiber having an incident end of the laser light on another end side in the package, the another end being in an opposite direction of an emission direction in which the semiconductor laser device emits the laser light; and a turn-back unit that turns back the laser light toward the another end side in the package, the another end being in the opposite direction of the emission direction in which the semiconductor laser device emits the laser light, and outputs the laser light to the incident end of the optical fiber.

The first capacitor is opposed to and electrically connected to the first back electrode. The second capacitor is opposed to and electrically connected to the second back electrode. Each of the first circuit and the second circuit has a main region that overlaps with a corresponding one of the first capacitor and the second capacitor. At least one circuit of the first circuit and the second circuit has an extension region extending from the main region toward another circuit of the first circuit and the second circuit. At least one of one of the pair of first wires and the second wire is bonded to the extension region.

The optical module includes: a housing having first and second end walls and a pair of side walls; a semiconductor laser element; a first TEC; a wavelength locker unit including an optical splitting component and an etalon filter; and a second TEC. The second end wall is provided with a feedthrough. The pair of side walls is not provided with an external connection terminal. The second TEC is disposed between the first TEC and the second end wall and has: a first substrate thermally coupled to a bottom surface of the housing; a second substrate thermally coupled to the etalon filter; and a heat transfer part that transfers heat. The optical module further includes a wiring pattern that is arranged side by side with the heat transfer part and that supplies electric power to the first TEC from the feedthrough.

An optical module includes a light-forming part and a protective member. The light-forming part includes a base member; semiconductor light-emitting devices mounted on the base member; lenses mounted on the base member and configured to convert, in terms of spot size, light emitted from the semiconductor light-emitting devices; and light-receiving devices that are mounted on the base member, that are disposed, in the emission directions of the semiconductor light-emitting devices, between the semiconductor light-emitting devices and the lenses, and that are configured to directly receive light from the semiconductor light-emitting devices.

A thermo-electric cooling (TEC) system is presented for cooling of a device, such a laser for example. The TECT system comprises first and second heat pumping assemblies, and a control unit associated at least with said second heat pumping assembly. Each heat pumping assembly has a heat source from which heat is pumped and a heat drain through which pumped heat is dissipated. The at least first and second heat pumping assemblies are arranged in a cascade relationship having at least one thermal interface between the heat source of the second heat pumping assembly and the heat drain of the first heat pumping assembly, the heat source of the first heat pumping assembly being thermally coupled to the electronic device which is to be cooled by evacuating heat therefrom. The control unit is configured and operable to carry out at least one of the following: (i) operating said second heat pumping assembly to provide a desired temperature condition such that temperature of the heat drain of said first heat pumping assembly is either desirably low or by a certain value lower than temperature of the heat source of said first heat pumping assembly; and (ii) operating said second heat pumping assembly to maintain predetermined temperature of said thermal interface.

A technology of effectively interrupting light reflected from a wavelength selective filter so as not to be fed back to a laser diode chip in a semiconductor laser package having a function of adjusting a relative intensity ratio of a signal of “1” and a signal of “0” using an optical filter. Since an optical interruption device may effectively interrupt a light feedback to the laser diode chip by adjusting characteristics of a 45 degree partial reflection mirror in an existing TO-can type laser device having the 45 degree partial reflection mirror and additionally disposing one λ/4 waveplate, unlike previously known optical isolators using an existing Faraday rotator, the signals of “1” and “0” may be effectively adjusted in a TO-can type laser device having a small volume, thereby improving a function of communication.

An optical module with a semiconductor element, which integrates a semiconductor laser diode with an electro-absorption modulator, mounted on a carrier; and an optical transmitter apparatus implementing the optical modules are disclosed. The carrier of the optical module has a back metal connected to the ground on the top thereof through a metal provided in a side surface of the carrier but electrically isolated from the chassis ground of the optical transmitter apparatus. The optical transmitter apparatus installs a plurality of the optical modules on a thermos-electric cooler (TEC) in a top plate thereof. The top plate is electrically isolated from the chassis ground.

An optical communication package includes a circuit layer, an optical component electrically coupled to the circuit layer to optically communicate outside of the package, and a thermoelectric cooler electrically coupled to the circuit layer and disposed to transfer heat from the optical component to the circuit layer.

A Peltier effect heat transfer system (208) comprising: a plurality of heat transfer elements (301-308); wherein each heat transfer element (301-308) comprises at least one semiconductor element pair arranged to yield Peltier effect heat transfer, each semiconductor element pair comprising a P-doped semiconductor element (408) and an N-doped semiconductor element (410); and the heat transfer elements (301-308) are independent such that each heat transfer element (301-308) can be activated so as to yield Peltier effect heat transfer independently of each other heat transfer element (301-308).